Abstract

An unusual response in the luminescence measurements of GaN thin film and ZnO bulk crystal is observed at low temperatures. The authors demonstrate theoretically that such an unusual response is due to the longitudinal optical phonon mediated Fano resonance involved in the recombination process of the donor bound exciton. The line shapes obtained by the calculation in the present mechanism are in excellent agreement with the experimental results.

Received 17 October 2006Accepted 14 December 2006Published online 17 January 2007

Acknowledgments:

The work in Hong Kong was supported by the HK-RGC CERG (Grant No. HKU 7056/06P). One of the authors (K.J.J.) gratefully acknowledges research support from the Chinese National Foundation of Nature Sciences. The other author (S.J.X.) wishes to thank S. L. Shi, X. D. Luo, and J. N. Wang for their contributions in the PL measurements of ZnO.